Star Trek's greatest Klingon, Worf (Michael Dorn), rarely showed fear in Star Trek: The Next Generation or Star Trek: Picard, but he wasn't as intimidated by Captain Jean-Luc Picard (Patrick Stewart) as he was by a different bald Starfleet Captain. Worf was part of TNG's cast for all 7 seasons, and he appeared in all 4 TNG movies. After Star Trek Generations, however, Worf joined Star Trek: Deep Space Nine, and the Klingon became a key part of the DS9 cast from seasons 4 to 7.
After Star Trek: Deep Space Nine ended, Worf became the Klingon Ambassador as part of the House of Chancellor Martok (J.G. Hertzler), but he didn't remain long as the Klingon warrior was back on the USS Enterprise-E as Security Chief in Star Trek: Nemesis. Star Trek: Picard season 3 updated Worf's Starfleet career and revealed he succeeded Jean-Luc Picard as Captain of the USS Enterprise-E in the 2280s. However, Worf lost the Enterprise-E under mysterious circumstances that the Klingon insists were not his fault. In Star Trek: Picard season 3, Captain Worf was part of Starfleet Intelligence, and the Klingon played a key role in defeating the Borg once more and saving the United Federation of Planets at Frontier Day alongside Admiral Picard and the crew of the USS Enterprise-D. Meanwhile, at no point did Worf display any type of fear toward Picard, unlike the Klingon's time on Deep Space Nine.
